Clinical implications of the American Joint Committee on Cancer (AJCC) 8th edition update in seminoma pT1 subclassification

Abstract

<jats:title>Abstract</jats:title> <jats:p><jats:bold>Background </jats:bold>Seminoma accounts for 30-50% of Testicular Germ-Cell Tumors (TGCT) - the most common solid malignancy in men aged 15-35 years. The American Joint Committee on Cancer (AJCC) 8th edition (2018) created the subclassifications pT1a (tumor size &lt; 3 cm) and pT1b (≥ 3 cm), despite not universally recognized. The authors propose to further understand its potential impact in clinical practice, by reviewing current evidence and reviewing clinical cases at their institutions.<jats:bold>Methods: </jats:bold>All consecutive cases of seminoma stage I pT1 treated at two institutions between January 2005 and December 2016 were included. Clinical data were retrieved, and variables were analyzed using SPSS. Review of relevant literature on the topic.<jats:bold>Results:</jats:bold> Seminoma pT1 was identified in 58 patients. By using newly AJCC criteria, 29 (50.0%) would have been staged as pT1a and 29 (50.0%) pT1b. Median follow- up time 5.8 years. Three recurrences were recorded (2 in pT1a and 1 in pT1b, all under surveillance protocol); no deaths occurred. <jats:italic>Rete testis </jats:italic>invasion (RTI) and extensive necrosis (EN) were associated with pT1b (<jats:italic>P</jats:italic>&lt;0.0001 and P=0.023, respectively), therefore pT1b was associated with RTI and EN, known adverse biological features, but the clinical impact could not to be assessed with the present methodology. <jats:bold>Discussion: </jats:bold>In our population, the retrospective analysis of the newly created AJCC criteria showed no significant difference in recurrence or death, although pT1b was associated to adverse biological markers. Our results also confirm an excellent prognosis, regardless of subcategorization, thus a larger population and a longer follow-up time are needed to understand the impact of the recently updated criteria. We would recommend using the latest AJCC staging system, although the individual risk of relapse, long-term toxicities and patient preferences should be taken into account when considering surveillance or active treatment options.</jats:p>